The invention relates to a device for opening capsules, which device is integrated into an inhaler and comprises a capsule receiver comprising a capsule chamber, which extends in a first direction (X) in the manner of a tube and in which a capsule (2) can be arranged, and a puncture device for opening the capsule, which puncture device is arranged in a second radial direction (Y) with respect to the capsule chamber, the puncture device having at least one needle which is moveable in part into the capsule chamber along the second direction (Y) by means of an actuating button.
Several principles by which inhalers operate are known in the prior art. The present invention relates to inhalers for the inhalation of medicaments in powder form from capsules. Such inhalers according to the invention are also called Bernoulli inhalers and are available on the market under the name HandiHaler, for example. The active ingredient in powder form is thereby stored in a capsule. These capsules are conventionally made of hard gelatine and consist of two cylindrical parts which are hemispherical at their ends. Such a capsule is disclosed in document DE 198 35 346 A1, for example.
Such a capsule is introduced into a generally cylindrical capsule chamber of the inhaler. This capsule chamber has an air inlet channel at one of its axial ends and an air outlet channel, which extends to the mouthpiece, at a further axial end. Furthermore, the dimensions of the capsule chamber are such that its length and width are greater than the dimensions of the capsule. However, the axial longitudinal axis of the capsule is nevertheless arranged substantially in parallel with an axial longitudinal axis of the capsule chamber.
Before inhalation, the capsule must first be opened. The inhaler has a puncture or cutting device for this purpose. This puncture device comprises two needles which are spaced apart along an axis in parallel with the axial longitudinal axis of the capsule chamber. The needles are pressed against the capsule by an actuating button, so that two openings are formed in the longitudinal lateral surface of the capsule. Some types of capsule have corresponding tapered portions of material at the puncture sites.
If air is then drawn in through the mouthpiece, an air stream is created in the capsule chamber from the air inlet to the air outlet channel. The air stream flowing past the openings generates a low pressure in front of the capsule openings compared with the interior of the capsule, so that the powder in the capsule is entrained in the air stream and thereby nebulised. In addition, the air stream causes the capsule to vibrate predominantly along the axial longitudinal axis. Owing to the dimensions of the capsule chamber already mentioned, the capsule is able to vibrate both vertically and horizontally.
Such inhalers are disclosed, for example, in documents DE 39 27 170 A1, DE 33 45 722 A1 and DE 43 18 455 A1.
Such inhalers of the generic type are disadvantageous in that the needles for opening the capsule are fixed directly to the actuating button. When the actuating button is moved, the needles scrape off plastics material at the openings in the capsule chamber owing to the tolerances. This creates plastics particles which lie in the region of the inhalation path. Furthermore, false air is drawn in through the needle openings in the capsule chamber. Some of the capsule inhalers available on the market additionally exhibit appreciable canting as well as in some cases an audible sound due to the unclear tolerance chains upon actuation of the actuating button.
Accordingly, the object of the present invention is to provide a device for opening capsules which is integrated into an inhaler, and respectively an inhaler having such a device, which avoid the disadvantages mentioned at the beginning.